Apparatus for producing metal bodies



Jan. 9, 1945. R. K. HOPKINS APPARATUS FOR PRODUCING METAL. BODIES FiledMay 8, 1943 INVENTOR Roberiljya akam ATTORNEY ing stool.

Patented Jan. 9, 1945 APPARATUS FOR PRODUCING METAL BODIES r Robert K.Hopkins, New York, N. Y., assig'nor to. The M. W. Kellogg Company, NewYork, N. Y;, a corporation of Delaware Application May 8,1943, SerialNo. 486,479

' 2 Claims. (01. 22-512) The present invention relates-to the'art ofproducing and casting metal ingots.

- Ingotscan be cast by producing and. depositing molten metal in afumace'and withdrawing the solidified metal from said furnace eithercontinuously or by a step by step movement. It is a difficult problem toprovide a'satisfactory anchorage for the initially deposited metal sothat the solidified metal can be withdrawn from the furnace. If astarting plug is employed as a support and anchorage for the initiallydeposited metal, the plug must be made of finished metal of the desiredanalysis thereby increasing the cost. Also, since the plug section mustsubsequently be cropped from the final in'got the I metal yield isreduced.

Various other objects, features and advantages of the invention will beapparent from the following'particular description, and from aninspection of the accompanying drawing which shows a diagrammaticvertical section of a form of apparatus which embodies thepresentinvention, and which may be employed to carry out the process of theinvention.

Referring to the drawing, there is shown an apparatus which may beemployed in accordance with the present invention'to continuously forman ingot of finite predetermined length. This apparatus includes aningot mold furnace l0 One object of the .present invention is to providea new and improved continuous casting. ap-

paratus affording an effective pulling grip on the solidified metal inthe furnace without the use of a starting plug, so that end scrap lossin the final ingot is avoided.

Another object is to provide a new and improved continuous casting"method by which the use of a starting .plug is avoided and end scraploss in' the final ingot eliminated.

In carrying out the features of the present invention, there is provideda tubular mold furnace having its bottom initially closed by a start-This startingstool is provided with an indenture into which the moltenmetal roduced and. deposited in the furnace flows to orm an ingotprojection. The retention 'ofthis ingot projection in the starting stoolindentureafiords an effective anchorage between the stool and the bottom'of the ingot, so that withdrawal of the ingot from the tubular moldfurnace can be effected by the movement of the stool axially away fromsaid furnace. The starting stool is section-' alized to permit itsremoval from the ingot at the'end of the operations.

The end section of the ingot having the stool anchoring conformation isof the same analysis and forms an integral part 0f,the rest of theingot, and therefore can be worked with the rest oftheingot.

As another featureof' the present invention, the method'and apparatus ofthe present invention above referred to is employed in conjunction' withthe electric fusion method of producing metals in which an electrode issubmerged 1 in a protective layer of flux to create a metal fus ng'zoneand metal ingredients are fed into this zone, fused therein and e thendeposited below the flux-layenfiwhich may be of any suitable hollowshape, but which is shown in' the form of an upright cylindrical tubeThis mold I0 may be of suitable refractory material, or may be of metalsuch as copper hollowed as shown to form a jacket H for the circulationof a suitable cooling medium therethrough such as water.

During the preliminary stages of the metal producing and castingoperations in the mold furnace 10, the lower end of this furnace isclosed by a base,member I2 which serves not only as r a startingstool,-but also serves as a means by which the cast ingot A is grippedand pulled away from the mold furnace. For that purpose,

themember l2 comprises two semicircular ingot clamping segments -I3releasably fastened together by any suitable means, as for example bybolts l5 passing through lugs N3 in the two segments. These stoolsegments l3 conjointly define a recess l8 with a bead indenture '20. Themetal which is produced and deposited in this stool recess l8 forms anenlarged head 2| with a radially outwardly extending bead or projection22. This bead conformation 22 on the cast ingot affords an effectivegrip or anchorage for thestarting stool I 2 as it is movedaway from themold furnace III to cause withdrawal. of the cast ingot A from said moldfurnace.

The starting stool segments l3 may be of suitable refractory material,or may be of metal such as copper hollowed to form a jacket 23 for thecirculation of cooling water therethrough as shown.

The metal is produced and deposited in the mold furnace l0 and thestarting stool l2- desirably by the use of 'a flux submerged electrodedevice which maybe of the general type shown in my. U. S. Patent No.2,151,914fissued March" ,28, 1939, and No. 2,191,479, issued February27, 1940. For that purpose, there may-be provided a consumable hollowelectrode extending in I are fed at controlled rates to the gap betweenthe end of said electrode and the pool'of molten metal 30 by suitablemeans, as for instance that shown in my Patent No. 2,191,479 abovereferred to. The hollow electrode 26 may be continuously shaped from ametal strip as shown in said patent.

I .If desired, the electrode 28 may be non-consumable, and all of thenecessary metallic constituents to make up a metal of desired analysismay be fed in fluent or more solid form into the metal fusing zonecreated by the electrode.

The electrode 26 is submerged in a floating layer or blanket of flux 28of any suitable composition which does not produce anobjectionable'amount of gas under the influence of an electricdischarge, and which has the required refining effect on the fusedmetal. Flux comprising silicates or components of silicates, such asmanganese silicate, calcium silicate, aluminum ed, a. metal 2| in saidstarting stool is solidi-- fled and hardened to a sufllcient extent toafford a solid anchorage for said starting stool.

- During the ingot withdrawal operations, the furnace l0 may be shakenor revolved slowly with respect to the starting stool it to facilitateremoval of the ingot A from said furnace.

The axial continuous movement of the starting stool l2 away from themold furnace iii may be controlled at a rate whichis equal to or great.

er than the rate at which the metal is produced and deposited in thefurnace W. This rate of silicate, glass and the like have been foundsuitable for this purpose. This flux layer 28 serves to refine the metalas it is produced, protect it against atmospheric contamination andinsulate the metal against rapid heat loss. I

The electrode 26, the mold furnace I0 and the stool l2 are electricallyconnected in the same circuit to discharge current across the gapbetween the electrode 26 and the body of deposited molten-metal 30.

Any suitable means may b provided for continuously pulling the startingstool l2 away from the mold furnace ll). For example, the stool segmentsB may have dove-tail slide connections 32 to the upper end of a feedscrew 33 moved axially through an axially fixed worm wheel 34 which isthreaded on said feed screw and which is driven from a worm 35.

In the operation of the method illustrated in Fig. 1, at the start ofoperations, the stool l2 s is disposed in engagement with the lower endof the mold furnace Ill. The metal producing and depositing operationsare initiated with the electrode 2'6near the bottom of the stool If inthe presence of the flux 28. A quantity of the desired metal in the formof grindings or chips is placed in the bottom of stool l2 to protect thebottom wall of the stool from direct contact with the electric currentdischarge at the beginning of the operations. A quantity of the rawmaterials of the desired metal in granular form and in the properproportions may be used for this purpose if preferred.

As the metal is produced and deposited. in the stool l2 and the mold l0,and the level of the molten metal rises, the electrode 26 is movedupwardly to maintain a gap of constant length between, the lower end ofthe electrode 26 and the upper level of the deposited molten metal 30.After the molten metal 30 has reached a predetermined level in the moldfurnace III, the starting stool IZ-is moved axially and continuouslyaway from the mold furnace Hi. When this axial movement of the startingstool I 2 is initiatmetal production may be controlled by regulating therate of electrode feed and the rate of feed of the other metalconstituents which may be delivered in fluent form into the fusing zoneInstead of withdrawing the solidified metal from the furnace l0.continuously, this withdrawal may be effected by a step by stepoperation. For example, if a predetermined solid section of the ingothas been slowly withdrawn from the mold furnace, this ingot withdrawalis interrupted and the electrode 26 is lowered until its lower end issubmerged in the flux 28 and spaced from the surface of the moltenmetal. The electric metal fusing and depositing operation is thencontinued to produce and deposit metal in the mold furnace, and therebyfill up the furnace space left vacant by the previous ingot withdrawaloperation. During the gradual withdrawal of the ingot, the metal fusingand depositing operations need not be interrupted, but the electrode 28may be made to mov in unison with the withdrawingingot, and the electricdischarge through the gap may be continued during this withdrawal.

After the metal in the furnace it has been produced up to apredetermined level again, the movement of the starting stOOl I2 awayfrom. the mold furnace I0 is resumed until another ingot section ofpredetermined length has been pulled out of said furnace; This step bystep with-. drawal of the ingot is continued until an ingot ofpredetermined length has been produced.

As many changes ca'n be made in the above method and apparatus, and manyapparently widely different embodiments of this invention can be madewithout departing [from thescope of the claims, it is intended that allmatter contained in the above description or shown in 3 the accompanyingdrawing shall be intenpreted as illustrative and not in a limitingsense.

What is claimed is:

1. An ingot casting apparatus comprising an open ended tubular mold, aconcave mold stool adapted to close the bottom end of said mold, meansfor moving said stool axially away from said mold, said stool having aningot anchoring bead recess extending radially outwardly from its hollowand around the entire periphery of said hollow, said stool comprisingtwo hollow walled complementary sections, means for circulating acooling medium through each of said sections, means releasably securingsaid sections together to permit separation of said sections for removalof said sections from the' ingot, and means for depositing molten metalinto said mold and said stool. V

2. An ingot casting apparatus comprising a hollow-walled, open-endedtubular mold, means .for circulating a, cooling medium through thehollow walls of said mold, a concave mold stool adapted to close thebottom end of said mold, said stool having an ingot anchoring beadrecess extending radially outwardly from'its hollow and I said sectionsfrom the ingot end, electrode means adapted to deposit molten metal insaid stool and mold beneath the surface of a protective blanket of flux,and means for. moving said stool away from said mold to withdraw metalfrom said mold as it solidifies. v

ROBERT K. HOPKINS.

